The present invention relates to a termination unit for a through the wall horizontal vent of a coaxial flue pipe and wherein the termination unit is capable of dampening wind up to about 65 m.p.h. to prevent the pilot flame in the combustion chamber from extinguishing due to air disturbance propagating to the pilot flame.
Various types of termination unit designs are known and examples thereof are illustrated in U.S. Pat. Nos. 2,998,764, 4,940,042 and 3,435,816, which are believed to represent the closest prior art. All of these termination units are efficient in dampening wind striking against the unit in the area of the air intake but are efficient to a maximum wind speed of up to 45 m.p.h. On occasion, the pilot flame in a combustion furnace, hot water heater, etc., has been known to extinguish by a gust of air entering the termination unit, air feed conduit and propagating in a down draft to the pilot flame through the coaxial air feed passage. It is therefore desirable to provide a termination unit design which will be efficient in dampening wind at velocities higher than 45 miles per hour whereby to provide added security to combustion devices. If a pilot flame is extinguished, as is the case with some prior art designs, gas can infiltrate an area where the gas combustion device is used and could result in disastrous circumstances should the equipment not be provided with flame sensor and automatic gas shut-off valves. When the pilot is extinguished, there is often the need to have the burner serviced, and this is costly.
It is a feature of the present invention to provide a termination unit which substantially overcomes the disadvantages of the prior art and which is capable of dampening wind striking the termination unit at velocities of up to about 60 to 70 m.p.h.
According to the above feature, from a broad aspect, the present invention provides a termination unit for a through-the-wall horizontal vent of a gas combustion device having a combustion chamber and a burner. The termination unit comprises wall mounting means securable to a vertical wall outer surface and about an outer sleeve of a coaxial flue pipe. A fresh air chamber is secured to the wall mounting means. An exhaust end of an exhaust flue pipe extends through the wall mounting means and the fresh air chamber to exit through an outer wall of the chamber. Air intake ports are provided in an outer peripheral wall of the chamber to supply fresh air to a co-axial passage between the exhaust flue pipe and the outer sleeve to feed the combustion chamber. Air baffle means is provided in the chamber about the exhaust end of the flue pipe and extends through the chamber. Wind deflector means is disposed in spaced relationship about the air intake ports of the chamber.